David Cameron's 'porn filter' will make no difference, say ISPs

ISPs have insisted that David Cameron's 'porn filter' plan will only apply to new broadband subscribers. Photograph: Dan Chung for the Guardian

Claims that David Cameron has forced a new "porn filter" on UK internet content have been disavowed by internet service providers, which said that the vast majority of customers will see "absolutely no difference" to their web content.

Confusion arose after it was suggested that a new "filtered feed" system will be applied to everyone using internet connections provided by the biggest four ISPs – BT, TalkTalk, Virgin and Sky, which between them have 17.6 million of the 19.2 million broadband customers in the UK.

It was claimed that the prime minister would unveil the measures on Tuesday as he hosted a No 10 meeting with the Mothers' Union, which earlier this year produced a raft of proposals to shield children from sexualised imagery.

But ISPs moved quickly to insist that the provisions will only apply to people taking out completely new contracts, who will be offered the choice of a connection with "parental controls", or one without. "Customers will have to choose one or the other, but we won't be making either one the default," said a source at one of the ISPs. A spokesperson for TalkTalk said: "This is called 'active choice' rather than an opt-in or opt-out." People who change to a different tier of connection within the same service will not be obliged to change the setting. BT said that new customers will be offered a package of parental control systems, provided by the security company McAfee.

However, it is highly unlikely that the initiative to be announced by Cameron will make any noticeable impact on UK web browsing. Very few people take out new contracts: during a typical quarter, fewer than 5% of any ISP's customers change provider. Data from uSwitch suggests about 12 million people have not changed their broadband contract in the past year, and 5 million who have never changed it.

In a statement, the ISPs said: "BT, Sky, TalkTalk and Virgin Media are pleased to have developed and agreed a code of practice, including measures to ensure that customers are provided with an active choice as to whether to activate parental controls in the home.

"The four internet service providers have worked closely with government and a range of stakeholders to swiftly introduce measures addressing recommendations set out in the Bailey report.

"The ISPs have committed to improve the way they communicate to customers, enabling parents to make simple and well-informed choices about installing and activating parental controls and other measures to protect children online. The four ISPs are working with parents' groups and children's charities on this important initiative and will continue to do so."

But questions have been raised about the systems used to implement the blocking, for which TalkTalk will use a service called HomeSafe. As implemented by TalkTalk, every web location that a customer connects to will be recorded and checked for malicious software – even if they have not opted into the "parental control" system.

The prime minister is expected to announce other moves in line with the Christian charity's review, such as restrictions on aggressive advertising campaigns and certain types of images on billboards.

There will also be a website, ParentPort, which parents can use to complain about television programmes, advertisements, products or services they believe are inappropriate for children.

The site, which will direct complaints to the regulator dealing with that specific area of concern, is expected to be run by watchdogs including the Advertising Standards Authority, BBC Trust, British Board of Film Classification, Ofcom, Press Complaints Commission, Video Standards Council and Pan European Game Information.

Cameron gave strong backing in June to the Mothers' Union proposals after he commissioned a six-month review by the charity's chief executive, Reg Bailey. However, Cameron did not commit to legislation.

Bailey's recommendations included providing parents with one single website to make it easier to complain about any programme, advert, product or service, putting age restrictions on music videos and ensuring retailers offer age-appropriate clothes for children.

Cameron wrote to Bailey in June to thank him for his report. "I very much agree with the central approach you set out," the letter said.

"As you say, we should not try and wrap children in cotton wool or simply throw our hands up and accept the world as it is. Instead, we should look to put 'the brakes on an unthinking drift towards ever-greater commercialisation and sexualisation'."

Bailey's report asked for government and business to work together on initiatives such as ending the sale of inappropriately "sexy" clothing for young children, for example underwired bras and T-shirts with suggestive slogans.

However, he recommended that if retailers do not make progress on the issue they should be forced to make the changes in 18 months.